What does "MRI" stand for and how does it work?

MRI stands for magnetic resonance imaging. It uses a powerful magnetic field and radiofrequency pulses to create detailed cross-sectional images of internal body structures without using ionizing radiation. Hydrogen atoms in body tissues align with the magnetic field, and when radiofrequency pulses are applied, the atoms emit signals that a computer converts into images. MRI excels at imaging soft tissues including the brain, spinal cord, joints, muscles, and abdominal organs. Contraindications include certain metallic implants, pacemakers, and cochlear implants.